Yeah, I'm confused by this whole thing too. The tiny QR code looks different from my original QR code. However, whenever I log in (via the edit registration tab), I am still presented with my original QR code.

In the three years they've used QR codes (2014, 2015, and this year) the e-mailed code and the log-in and reprint code have looked different. Both in 2014 and 2015 I presented the larger original code and had no issue. Although, as has been said above, I also had the smaller later sent one with me just in case.